esp-idf/components/esp_hw_support/esp_async_memcpy.c

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// Copyright 2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "hal/dma_types.h"
#include "esp_compiler.h"
#include "esp_heap_caps.h"
#include "esp_log.h"
#include "esp_async_memcpy.h"
#include "esp_async_memcpy_impl.h"
static const char *TAG = "async_memcpy";
#define ASMCP_CHECK(a, msg, tag, ret, ...) \
do \
{ \
if (unlikely(!(a))) \
{ \
ESP_LOGE(TAG, "%s(%d): " msg, __FUNCTION__, __LINE__, ##__VA_ARGS__); \
ret_code = ret; \
goto tag; \
} \
} while (0)
/**
* @brief Type of async mcp stream
* mcp stream inherits DMA descriptor, besides that, it has a callback function member
*/
typedef struct {
dma_descriptor_t desc;
async_memcpy_isr_cb_t cb;
void *cb_args;
} async_memcpy_stream_t;
/**
* @brief Type of async mcp driver context
*/
typedef struct async_memcpy_context_t {
async_memcpy_impl_t mcp_impl; // implementation layer
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portMUX_TYPE spinlock; // spinlock, prevent operating descriptors concurrently
intr_handle_t intr_hdl; // interrupt handle
uint32_t flags; // extra driver flags
dma_descriptor_t *tx_desc; // pointer to the next free TX descriptor
dma_descriptor_t *rx_desc; // pointer to the next free RX descriptor
dma_descriptor_t *next_rx_desc_to_check; // pointer to the next RX descriptor to recycle
uint32_t max_stream_num; // maximum number of streams
async_memcpy_stream_t *out_streams; // pointer to the first TX stream
async_memcpy_stream_t *in_streams; // pointer to the first RX stream
async_memcpy_stream_t streams_pool[0]; // stream pool (TX + RX), the size is configured during driver installation
} async_memcpy_context_t;
esp_err_t esp_async_memcpy_install(const async_memcpy_config_t *config, async_memcpy_t *asmcp)
{
esp_err_t ret_code = ESP_OK;
async_memcpy_context_t *mcp_hdl = NULL;
ASMCP_CHECK(config, "configuration can't be null", err, ESP_ERR_INVALID_ARG);
ASMCP_CHECK(asmcp, "can't assign mcp handle to null", err, ESP_ERR_INVALID_ARG);
// context memory size + stream pool size
size_t total_malloc_size = sizeof(async_memcpy_context_t) + sizeof(async_memcpy_stream_t) * config->backlog * 2;
// to work when cache is disabled, the driver handle should located in SRAM
mcp_hdl = heap_caps_calloc(1, total_malloc_size, MALLOC_CAP_8BIT | MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL);
ASMCP_CHECK(mcp_hdl, "allocate context memory failed", err, ESP_ERR_NO_MEM);
mcp_hdl->flags = config->flags;
mcp_hdl->out_streams = mcp_hdl->streams_pool;
mcp_hdl->in_streams = mcp_hdl->streams_pool + config->backlog;
mcp_hdl->max_stream_num = config->backlog;
// circle TX/RX descriptors
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for (size_t i = 0; i < mcp_hdl->max_stream_num; i++) {
mcp_hdl->out_streams[i].desc.dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_CPU;
mcp_hdl->out_streams[i].desc.next = &mcp_hdl->out_streams[i + 1].desc;
mcp_hdl->in_streams[i].desc.dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_CPU;
mcp_hdl->in_streams[i].desc.next = &mcp_hdl->in_streams[i + 1].desc;
}
mcp_hdl->out_streams[mcp_hdl->max_stream_num - 1].desc.next = &mcp_hdl->out_streams[0].desc;
mcp_hdl->in_streams[mcp_hdl->max_stream_num - 1].desc.next = &mcp_hdl->in_streams[0].desc;
mcp_hdl->tx_desc = &mcp_hdl->out_streams[0].desc;
mcp_hdl->rx_desc = &mcp_hdl->in_streams[0].desc;
mcp_hdl->next_rx_desc_to_check = &mcp_hdl->in_streams[0].desc;
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mcp_hdl->spinlock = (portMUX_TYPE)portMUX_INITIALIZER_UNLOCKED;
// initialize implementation layer
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async_memcpy_impl_init(&mcp_hdl->mcp_impl);
*asmcp = mcp_hdl;
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async_memcpy_impl_start(&mcp_hdl->mcp_impl, (intptr_t)&mcp_hdl->out_streams[0].desc, (intptr_t)&mcp_hdl->in_streams[0].desc);
return ESP_OK;
err:
if (mcp_hdl) {
free(mcp_hdl);
}
if (asmcp) {
*asmcp = NULL;
}
return ret_code;
}
esp_err_t esp_async_memcpy_uninstall(async_memcpy_t asmcp)
{
esp_err_t ret_code = ESP_OK;
ASMCP_CHECK(asmcp, "mcp handle can't be null", err, ESP_ERR_INVALID_ARG);
async_memcpy_impl_stop(&asmcp->mcp_impl);
async_memcpy_impl_deinit(&asmcp->mcp_impl);
free(asmcp);
return ESP_OK;
err:
return ret_code;
}
static int async_memcpy_prepare_receive(async_memcpy_t asmcp, void *buffer, size_t size, dma_descriptor_t **start_desc, dma_descriptor_t **end_desc)
{
uint32_t prepared_length = 0;
uint8_t *buf = (uint8_t *)buffer;
dma_descriptor_t *desc = asmcp->rx_desc; // descriptor iterator
dma_descriptor_t *start = desc;
dma_descriptor_t *end = desc;
while (size > DMA_DESCRIPTOR_BUFFER_MAX_SIZE) {
if (desc->dw0.owner != DMA_DESCRIPTOR_BUFFER_OWNER_DMA) {
desc->dw0.suc_eof = 0;
desc->dw0.size = DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
desc->buffer = &buf[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
size -= DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
} else {
// out of RX descriptors
goto _exit;
}
}
if (size) {
if (desc->dw0.owner != DMA_DESCRIPTOR_BUFFER_OWNER_DMA) {
end = desc; // the last descriptor used
desc->dw0.suc_eof = 0;
desc->dw0.size = size;
desc->buffer = &buf[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += size;
} else {
// out of RX descriptors
goto _exit;
}
}
_exit:
*start_desc = start;
*end_desc = end;
return prepared_length;
}
static int async_memcpy_prepare_transmit(async_memcpy_t asmcp, void *buffer, size_t len, dma_descriptor_t **start_desc, dma_descriptor_t **end_desc)
{
uint32_t prepared_length = 0;
uint8_t *buf = (uint8_t *)buffer;
dma_descriptor_t *desc = asmcp->tx_desc; // descriptor iterator
dma_descriptor_t *start = desc;
dma_descriptor_t *end = desc;
while (len > DMA_DESCRIPTOR_BUFFER_MAX_SIZE) {
if (desc->dw0.owner != DMA_DESCRIPTOR_BUFFER_OWNER_DMA) {
desc->dw0.suc_eof = 0; // not the end of the transaction
desc->dw0.size = DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
desc->dw0.length = DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
desc->buffer = &buf[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
len -= DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
} else {
// out of TX descriptors
goto _exit;
}
}
if (len) {
if (desc->dw0.owner != DMA_DESCRIPTOR_BUFFER_OWNER_DMA) {
end = desc; // the last descriptor used
desc->dw0.suc_eof = 1; // end of the transaction
desc->dw0.size = len;
desc->dw0.length = len;
desc->buffer = &buf[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += len;
} else {
// out of TX descriptors
goto _exit;
}
}
*start_desc = start;
*end_desc = end;
_exit:
return prepared_length;
}
static bool async_memcpy_get_next_rx_descriptor(async_memcpy_t asmcp, dma_descriptor_t *eof_desc, dma_descriptor_t **next_desc)
{
dma_descriptor_t *next = asmcp->next_rx_desc_to_check;
// additional check, to avoid potential interrupt got triggered by mistake
if (next->dw0.owner == DMA_DESCRIPTOR_BUFFER_OWNER_CPU) {
asmcp->next_rx_desc_to_check = asmcp->next_rx_desc_to_check->next;
*next_desc = next;
// return if we need to continue
return eof_desc == next ? false : true;
}
*next_desc = NULL;
return false;
}
esp_err_t esp_async_memcpy(async_memcpy_t asmcp, void *dst, void *src, size_t n, async_memcpy_isr_cb_t cb_isr, void *cb_args)
{
esp_err_t ret_code = ESP_OK;
dma_descriptor_t *rx_start_desc = NULL;
dma_descriptor_t *rx_end_desc = NULL;
dma_descriptor_t *tx_start_desc = NULL;
dma_descriptor_t *tx_end_desc = NULL;
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size_t rx_prepared_size = 0;
size_t tx_prepared_size = 0;
ASMCP_CHECK(asmcp, "mcp handle can't be null", err, ESP_ERR_INVALID_ARG);
ASMCP_CHECK(async_memcpy_impl_is_buffer_address_valid(&asmcp->mcp_impl, src, dst), "buffer address not valid", err, ESP_ERR_INVALID_ARG);
ASMCP_CHECK(n <= DMA_DESCRIPTOR_BUFFER_MAX_SIZE * asmcp->max_stream_num, "buffer size too large", err, ESP_ERR_INVALID_ARG);
// Prepare TX and RX descriptor
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portENTER_CRITICAL_SAFE(&asmcp->spinlock);
rx_prepared_size = async_memcpy_prepare_receive(asmcp, dst, n, &rx_start_desc, &rx_end_desc);
tx_prepared_size = async_memcpy_prepare_transmit(asmcp, src, n, &tx_start_desc, &tx_end_desc);
if ((rx_prepared_size == n) && (tx_prepared_size == n)) {
// register user callback to the last descriptor
async_memcpy_stream_t *mcp_stream = __containerof(rx_end_desc, async_memcpy_stream_t, desc);
mcp_stream->cb = cb_isr;
mcp_stream->cb_args = cb_args;
// restart RX firstly
dma_descriptor_t *desc = rx_start_desc;
while (desc != rx_end_desc) {
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
desc = desc->next;
}
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
asmcp->rx_desc = desc->next;
// restart TX secondly
desc = tx_start_desc;
while (desc != tx_end_desc) {
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
desc = desc->next;
}
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
asmcp->tx_desc = desc->next;
async_memcpy_impl_restart(&asmcp->mcp_impl);
}
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portEXIT_CRITICAL_SAFE(&asmcp->spinlock);
// It's unlikely that we have space for rx descriptor but no space for tx descriptor
// Both tx and rx descriptor should move in the same pace
ASMCP_CHECK(rx_prepared_size == n, "out of rx descriptor", err, ESP_FAIL);
ASMCP_CHECK(tx_prepared_size == n, "out of tx descriptor", err, ESP_FAIL);
return ESP_OK;
err:
return ret_code;
}
IRAM_ATTR void async_memcpy_isr_on_rx_done_event(async_memcpy_impl_t *impl)
{
bool to_continue = false;
async_memcpy_stream_t *in_stream = NULL;
dma_descriptor_t *next_desc = NULL;
async_memcpy_context_t *asmcp = __containerof(impl, async_memcpy_context_t, mcp_impl);
// get the RX eof descriptor address
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dma_descriptor_t *eof = (dma_descriptor_t *)impl->rx_eof_addr;
// traversal all unchecked descriptors
do {
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portENTER_CRITICAL_ISR(&asmcp->spinlock);
// There is an assumption that the usage of rx descriptors are in the same pace as tx descriptors (this is determined by M2M DMA working mechanism)
// And once the rx descriptor is recycled, the corresponding tx desc is guaranteed to be returned by DMA
to_continue = async_memcpy_get_next_rx_descriptor(asmcp, eof, &next_desc);
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portEXIT_CRITICAL_ISR(&asmcp->spinlock);
if (next_desc) {
in_stream = __containerof(next_desc, async_memcpy_stream_t, desc);
// invoke user registered callback if available
if (in_stream->cb) {
async_memcpy_event_t e = {0};
if (in_stream->cb(asmcp, &e, in_stream->cb_args)) {
impl->isr_need_yield = true;
}
in_stream->cb = NULL;
in_stream->cb_args = NULL;
}
}
} while (to_continue);
}